The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and b...The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and benzoic acid as the transferred substance between water and oil. The results show that, with lance level of 2.1m and the top blowing rate of 25000Nm3/h, the volumetric mass transfer coefficient changes most significantly when the bottom blowing rate ranges from 384 to 540Nm3/h. The volumetric mass transfer coefficient reaches its maximum when the lance level is 2.1m, the top blowing rates is 30000Nm3/h, and the bottom blowing rate is 384Nm3/h with tuyeres located symmetrically at 0.66D of the converter bottom.展开更多
The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model...The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range ofg0- 110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company （CISC） converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm^3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm^3/h in the second phase, and 1040-1120 mm and 200-350 Nm^3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
针对模块化多电平换流器(modular multilevel converter,MMC)高压直流输电技术(high voltage direct current,HVDC)受端交流系统故障引起的直流过电压问题,文中提出一种基于晶闸管的模块化组合式直流泄能装置拓扑及协调控制方法。该直...针对模块化多电平换流器(modular multilevel converter,MMC)高压直流输电技术(high voltage direct current,HVDC)受端交流系统故障引起的直流过电压问题,文中提出一种基于晶闸管的模块化组合式直流泄能装置拓扑及协调控制方法。该直流泄能拓扑包括模块化分布式泄能部分、限流电抗器和集中式泄能电阻3部分,对子模块工作模式进行设计,提出可避免直流泄能装置反复投切的弹性调节泄能的协调控制策略,推导直流泄能装置功率控制及其内部电气耦合关系,给出泄能装置元件参数的设计方法。最后,基于PSCAD/EMTDC搭建MMC-HVDC及所提出的直流泄能装置模型,研究单相和三相接地故障下直流泄能装置的特性及直流过电压抑制效果。结果表明,所提直流泄能装置在协调控制策略下能够分阶段弹性调节泄能功率,有效抑制直流过电压,并有利于故障后的快速恢复。展开更多
文摘The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and benzoic acid as the transferred substance between water and oil. The results show that, with lance level of 2.1m and the top blowing rate of 25000Nm3/h, the volumetric mass transfer coefficient changes most significantly when the bottom blowing rate ranges from 384 to 540Nm3/h. The volumetric mass transfer coefficient reaches its maximum when the lance level is 2.1m, the top blowing rates is 30000Nm3/h, and the bottom blowing rate is 384Nm3/h with tuyeres located symmetrically at 0.66D of the converter bottom.
文摘The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range ofg0- 110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company （CISC） converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm^3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm^3/h in the second phase, and 1040-1120 mm and 200-350 Nm^3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated. 2008 University of Science and Technology Beijing. All rights reserved.
基金supported by National High-tech Research and Development Program of China（863 Program）（2009AA04Z416） National Science Foundation of China（51021005） Scientific Innovation of Colleges and Universities（Project v-200704）
基金supported by National High-tech Research and Development Program of China（863 Program）（2009AA04Z416） National Science Foundation of China（51021005） Scientific Innovation of Colleges and Universities（200704）
文摘针对模块化多电平换流器(modular multilevel converter,MMC)高压直流输电技术(high voltage direct current,HVDC)受端交流系统故障引起的直流过电压问题,文中提出一种基于晶闸管的模块化组合式直流泄能装置拓扑及协调控制方法。该直流泄能拓扑包括模块化分布式泄能部分、限流电抗器和集中式泄能电阻3部分,对子模块工作模式进行设计,提出可避免直流泄能装置反复投切的弹性调节泄能的协调控制策略,推导直流泄能装置功率控制及其内部电气耦合关系,给出泄能装置元件参数的设计方法。最后,基于PSCAD/EMTDC搭建MMC-HVDC及所提出的直流泄能装置模型,研究单相和三相接地故障下直流泄能装置的特性及直流过电压抑制效果。结果表明,所提直流泄能装置在协调控制策略下能够分阶段弹性调节泄能功率,有效抑制直流过电压,并有利于故障后的快速恢复。
